FIG. 1 is a flow chart depicting a conventional method 10 for fabricating a conventional perpendicular magnetic recording (PMR) transducer. For simplicity, some steps are omitted. A conventional, beveled PMR pole is provided, via step 12. The conventional pole is magnetic and has a top wider than its bottom. In addition, the conventional pole has a bevel. Thus, the conventional pole is shorter in the region of the air-bearing surface (ABS) location. The ABS location is the location at which the ABS will reside in the completed structure. The conventional pole may include a leading edge bevel, a trailing edge bevel, or both.
A conventional gap layer is deposited, via step 14. The conventional gap layer is nonmagnetic and may be insulating. The conventional gap layer is typically alumina deposited using atomic layer deposition (ALD). As a result, the conventional gap is conformal, covering the top and side of the conventional PMR pole. The conventional PMR head is then masked and a portion of the conventional gap layer milled, via step 16. The milling in step 16 removes a portion of the conventional gap layer from regions of the PMR transducer in which it is not desired. For example, the conventional gap layer is removed from the contacts for the PMR head.
A preclean is then performed, via step 18. The preclean is to prepare the conventional gap layer for deposition of the seed layer and shield. The preclean removes residues of the masking and milling of step 16 as well as a portion of the conventional gap layer. The conventional seed layer for the shield is then deposited, via step 20. For example, CoNiFe or NiFe might be used as the conventional seed layer. The conventional seed layer is a single layer provided in a single deposition in step 20. A wraparound shield may then be plated, via step 22.
FIGS. 2A-B depicts a portion of a conventional PMR transducer 50 formed using the conventional method 10. The conventional transducer 50 includes an underlayer 52, a conventional pole 54 including trailing bevel 56, a conventional gap 58, a conventional seed layer 60 and a conventional wraparound shield 62. Thus, using the conventional method 10, a pole 54 having a trailing edge bevel 56 and wraparound shield 62 may be formed.
Although the conventional method 10 may provide the conventional PMR transducer 50, there may be drawbacks. In particular, the preclean performed in step 18 may cause variations in the thickness of the conventional gap layer 58. The sloped portion of the conventional gap layer 58 on the sloped surface of the bevel 56 may etch at a different rate than the portion of the gap layer on the flat portions of the pole. As a result, there may be variations in the thickness of the conventional gap layer 58, particularly at or near the ABS location. For example, the conventional gap layer may be desired to be twenty-six nanometers thick. However, because of the uneven etching, the thickness of the conventional gap layer 58 may range from twenty-two through twenty-six nanometers. Such large variations result in variations in the profile of the magnetic field, which are quite undesirable. Accordingly, what is needed is an improved method for fabricating a PMR transducer.